Who needs an external on/off Wi-Fi button?I would argue a physical switch gives you one more thing to worry about. My guess is that these switches were put on by hardware makers in the early days of wi-fi due to poor software/battery life problems, and they've never been removed.

Best practice for overriding a pincode in a native iOS app?well i'd argue that license plate numbers are just as hard to remember as numbers UNLESS in your mind you can combine some of the letters into symbols. In your example, for instance, I can remember 'brase' as a single (phonetic) symbol, so i'm only required to remember 4 symbols total: 'brase', 'g', 'k', 'f'. (guess this is tangential to your original point)